Clot Chronicles: Anticoagulation in COVID-19 Patients – What are the Options?

Hi, my name is Dr. Jean Connors. I’m a hematologist at Brigham and Women’s Hospital and Dana-Farber Cancer Institute in Boston, Massachusetts. I’m going to speak about the use of direct oral anticoagulants (DOACs) in patients with COVID-19 infection for the Clot Chronicles of NATF. 

The COVID-19 pandemic has really hit all of us hard across the world – and more so in some places, including the United States. There are many lay press reports of a variety of thrombotic events occurring in patients, and there’s a significant uncertainty about how to manage routine anticoagulation as well as what we should do to prevent COVID-19 patients from developing thrombosis. 

As this is a new viral entity, the SARS-CoV-2, there are absolutely no data for managing this specific complication in patients with regard to thrombosis. To get a lay of the land, when reports first started coming out of China, there was this discussion about a coagulopathy. What we now know is that it’s not a coagulopathy in the sense that a hematologist thinks of it with a bleeding diathesis, but it’s definitely a hypercoagulable state. 

But what we know from the data that have been produced so far in reliable observational trials is that the increase in thrombosis is particularly strong in patients who are in the intensive care unit (ICU). So, for the patients who are COVID-19 positive but managing at home, those patients may not need anticoagulation. We have been advising patients with specific past thrombotic issues—particularly strong inherited thrombophilias or past history of DVT or PE—to contact their providers. 

But usually if these patients can stay home and have no other significant comorbid diseases, they do not need anticoagulation, as far as we can tell at this point. Even patients who are admitted to the hospital, who are on the inpatient floors, the ward, but not admitted to the ICU, they can continue with their standard anticoagulants, whether it be a DOAC or warfarin or others that they may be on. Although COVID-19 is associated with an increase in thrombosis, there is no reason to suspect that DOACs will not be effective. 

At our institution, we decided that for patients who are very unstable or in patients admitted to the intensive care unit, we will stop the DOAC or stop the warfarin; the half-life using low-molecular-weight heparin (LMWH) or unfractionated heparin is so much shorter that we can more readily control anticoagulation and allow it to wear off more quickly. 

So, there seems to be a concern that DOACs may be ineffective in the populations not in the ICU. We have no data to support that or suggest that, and we feel very comfortable using DOACs in the outpatient population or those patients admitted to the floor with mild or moderate symptoms from COVID-19. 

There is a mystique surrounding LMWH, and particularly unfractionated heparin, that it has anti-inflammatory properties and may actually have antiviral properties. While these data are often obtained from in vitro experiments in the laboratory, we do not have data to support that there is such a strong anti-inflammatory effect from LMWH or unfractionated heparin that patients should be preferentially switched to one of those agents simply for the anti-inflammatory properties. 

The small degree of anti-inflammatory mechanisms that are postulated to occur at the vascular endothelium may simple be overwhelmed by what we’re seeing on the pathology and autopsy reports, with direct viral infection on the vascular endothelial cells, apoptosis, release of high levels of procoagulant proteins, and lack of the normal protective antithrombotic effect of the vascular endothelial cells. The role that LMWH or unfractionated heparin would play in this milieu is undoubtedly pretty small. 

So, in summary, if you have a patient who is an outpatient on a DOAC, you should continue that DOAC even if they become COVID-19 positive and remain at home. If they are hospitalized, the severity of their illness dictates what should be done with anticoagulation. There are no data to suggest that DOACs are inferior to other anticoagulants in the setting of COVID-19. 

Thank you for your attention today to the Clot Chronicles.